Parasitic capacitance cancellation module for common mode EMI
This technology creates a 'negative capacitance' effect using a specially wound inductor with two coils of unequal turns connected at a midpoint, with a capacitor attached at that midpoint. The resulting negative capacitance can electrically cancel out unwanted parasitic capacitance that naturally builds up in power switching circuits. By canceling these parasitic effects, the circuit reduces common mode noise, cuts power losses, and allows switches to operate faster. It is a passive, component-level solution requiring no additional active circuitry.
What you could build
A drop-in filter or inductor module for power supply and motor drive manufacturers that suppresses common mode EMI without bulky external filters; target buyers are power electronics OEMs and industrial power supply makers seeking EMI compliance.
Who in Virginia should care
Virginia-based defense electronics and power systems contractors (e.g., supporting Navy shipboard power or data center power supply manufacturers in Northern Virginia) would have direct interest in EMI reduction techniques.
Readiness: Lab validated
Concept — described but not yet demonstrated. Lab validated — supported by experimental results in the patent. Prototype likely — the text describes a built, working embodiment.
Readiness is inferred from the patent text, not from a lab visit.
The record
- Inventors
- Shuo Wang, Fred C. Lee
- Granted
- October 13, 2009
- Status
- Granted patent
- Patent number
- 7602159
Ready to talk?
Virginia Tech Intellectual Properties handles licensing for this technology.
Prosim summaries are generated from public patent text and are not legal advice.